Conventionally, a connector which is comprised of a socket and a header is provided for electrically connecting between circuit boards, for example, an FPC and a hard board. A conventional connector mentioned in, for example, Japanese Laid-Open Patent Publication No. 2002-8753 is described with reference to FIGS. 10A to 10C, FIG. 11, FIGS. 12A to 12C and FIG. 13.
As shown in FIGS. 10A to 10C and FIG. 11, a socket 50 has a socket body 51 which is formed into a substantially flat rectangular parallelepiped shape by resin molding and a plurality of socket contacts 60 which is arranged on two lines along longitudinal direction of the socket body 51. Seen from front, a protruding table 53 of substantially rectangular parallelepiped shape is formed in a center portion of the socket body 51, and a plug groove 52 of substantially rectangular shape is formed between the protruding table 53 and each side wall 54 in longitudinal direction and each side wall 56 in widthwise direction. Mechanical strength of the socket body 51 is reduced due to forming the plug groove 52. Therefore, socket reinforcing metal fittings 56 are press-fitted into side walls 57 of the socket body 51 in widthwise direction.
The socked contact 60 is formed by bending a band metal into a predetermined shape by press working. A first contact portion 61 which is to be contacted with a header post 80 (referring to FIGS. 12A to 12C and FIG. 13) is formed at a first end portion of each socket contact 60 facing the plug groove 52. A first terminal portion 62 which is to be soldered on a conductive pattern of a circuit board is formed at a second end portion of the socket contact 60 positioned outward of the side wall 54. Each socket contact 60 is press-fitted after resin molding of the socket body 51. An end 56a of the socket reinforcing metal fitting 56 is press-fitted into the side wall 57 of the socket body 51 as mentioned above, and the other end 56b is soldered on a circuit board with the first terminal portion 62 of the socket contact 60.
On the other hand, as shown in FIGS. 12A to 12C and FIG. 13, a header 70 has a header body 71 which is formed in a shape of substantially flat rectangular parallelepiped by resin molding and a plurality of header post 80 which is arranged on two lines along longitudinal direction of the header body 71. An engaging groove 72 of substantially rectangular parallelepiped shape with which the protruding table 53 is engaged is formed at a position facing the protruding table 53 of the socket body 51. Flange portions 74 are formed on side walls 73 of the header body 71 so as to protrude substantially perpendicular to the side walls 73 from edges on rear face side (circuit board side) of the header body 71. Furthermore, engaging protrusions 75 which are to be engaged with key grooves 55 provided on the protruding table 53 of the socket 50 are formed at four positions on wall faces of the side walls 73 in side of the engaging groove 72 so that impact applied while the socket 50 and the header 70 are connected is dispersed. Header reinforcing metal fittings 76 are inserted into both end portions 77 of the header body 71 in longitudinal direction.
The header post 80 is formed by bending a band metal into a predetermined shape by press working. A second contact portion 81 which is to be contacted with the first contact portion 61 of the socket contact 60 is formed at a position of each header post 80 along an outer surface of the side wall 73. Furthermore, a second terminal portion 82 which is to be soldered on a conductive pattern of a circuit board is formed at an end portion protruding outward from the flange portion 74. Each header post 80 is integrally fixed on the header body 71 by insert molding while the header body 71 is molded by resin. An end 76a of the header reinforcing metal fitting 76 is inserted into the end portion 77 of the header body 71 as mentioned above, and the other end 76b is soldered on a circuit board with the second terminal portion 82 of the header post 80.
The socket 50 and the header 70 are mounted so that the first terminal portion 62 of each socket contact 60 and the second terminal portion 82 of each header post 80 are respectively soldered on conductive patterns of circuit boards. When the header 70 is engaged with the plug groove 52 of the socket 50, the protruding table 53 of the socket 50 is relatively engaged with the engaging groove 72 of the header 70, and the first contact portion 61 of the socket contact 60 contacts the second contact portion 81 of the header post 80 with elastic deformation. As a result, a circuit board on which the socket is mounted is elastically connected with a circuit board on which the header 70 is mounted.
Generally, when the plug groove 52, with which the header body 71 is engaged, is formed on the socket body 51, mechanical strength of the socket body 51 becomes weak so that it is easily deformed. In the above-mentioned conventional connector, in order to increase the mechanical strength of the socket body 51, the protruding table 53 is provided in the inside of the plug groove 52, and the engaging groove 72 which is to be engaged with the protruding table 53 is formed on the header body 71. Therefore, the conventional connector has a problem that dimensions in widthwise directions of the socket body 51 and the header body 71 becomes larger by the dimension of the protruding table 53.
Furthermore, since the socket reinforcing metal fittings 56 are press-fitted into the side walls 57 of the socket body 51, the side walls 57 become thick. Similarly, since the header reinforcing metal fittings 76 are inserted into both end portions 77 of the header body 71 in the longitudinal direction, a dimension of the header body 71 in the longitudinal direction becomes larger. Still furthermore, the plug groove 52 of the socket body 51 becomes longer in the longitudinal direction following that the dimension of the header body 71 in the longitudinal direction becomes larger. Consequently, there is a problem that the dimensions of not only the socket body 51 but also the connector itself become larger.